Purpose: In patients with aortic valve stenosis (AS) left ventricular stroke volume (LV_SV) is usually assessed by Doppler echocardiography (SV_LV-Doppler). In contrast, the assessment of LV_SV by LV planimetry by the modified Simpson’s rule (SV_LV-plan) is rarely used in AS patients.

The aim of the present study was to compare the assessment of SV_LV-Doppler and SV_LV-plan in relation to AS severity determined by the effective orifice area (EOA).

Methods and Results: 306 patients (mean age 78.1 ± 9 years) with severe AS defined by current guideline criteria were enclosed. Patients with concomitant defects of other valves were excluded. AS patients were divided into four subgroups based on mean pressure gradient (mPG) (low gradient-AS - LG-AS: mPG_AV < 40 mmHg; high gradient-AS - HG-AS: mPG_AV ≥ 40 mmHg) and indexed LV stroke volume (SVi) according to SV_LV-Doppler (low flow-AS - LF-AS: SVi ≤ 35 ml/m² and normal flow AS - NF-AS: SVi > 35 ml/m²). SV_LV-planwas assessed according to the current recommendations. Standardisation of apical views was verified by triplane data sets. In addition, Velocity Time Integral (VTI_LV-plan) was calculated by SV_LV-plan: VTI_LV-plan = SV_LV-plan /0.785 * diameter_LVOT². The EOA was calculated by the continuity equation based on SV_LV-Doppler (EOA-SV_LV-Doppler) and SV_LV-plan (EOA-SV_LV-plan). 

In NFLG-AS (SV_LV-Doppler = 75.3 ± 11.9 ml vs. SV_LV-plan = 63.4 ± 18.6 ml; n=91, p < 0.001) and NFHG-AS (SV_LV-Doppler = 84.7 ± 14.5 ml vs. SV_LV-plan = 66.4 ± 21.1 ml; n=61, p < 0.001) significant differences of LV_SVwere observed between Doppler echocardiography and LV planimetry. According to differences of SV_LV-Doppler and SV_LV-plan, EOA-SV_LV-Doppler and EOA-SV_LV-plan were significantly different in NFLG-AS (EOA-SV_LV-Doppler = 0.82 ± 0.13 cm² vs. EOA-SV_LV-plan = 0.69 ± 0.21 cm², p < 0.05) and NFHG-AS (EOA-SV_LV-Doppler = 0.73 ± 0.16 cm² vs. EOA-SV_LV-plan = 0.58 ± 0.17 cm², p < 0.05). 

In contrast to NF-AS subgroups, no significant differences were observed in LFLG-AS (SV_LV-Doppler = 48.6 ± 10.3 ml vs. SV_LV-plan = 50.5 ± 19.2 ml; n=133, p = 0.872) and LFHG-AS (SV_LV-Doppler = 55.2 ± 11.1 ml vs. SV_LV-plan = 56.4 ± 19.3 ml; n=21, p = 0.675). Inter- and intraobserver variabilities of SV_LV-Doppler and SV_LV-plan were < 5%.